The present invention relates to an apparatus for making packages of products wrapped with stretch plastic film.
In the current packaging industry, one of the uses of stretch plastic film is to wrap groups of products such as bottles with bases of different shapes—for example, circular, square or rectangular—or even containers made of metal or glass (and including parallelepiped shaped containers).
Machinery for wrapping groups of products with stretch film rather than heat shrink film or other materials has developed over the years because it has been found to be more economical to run and to have a simpler structure, while providing equally good wrapping quality.
In one prior art solution that uses stretch film, described in European patent application N.01830521.9 by the same Applicant as the present, the machine that implements a wrapping method based on stretch film essentially comprises:                a feed table on which the groups of products presenting a front face and a longitudinal dimension are formed;        a first station for making the packages, located on and forming part of the feed table, and being equipped with first means for unwinding the stretch film and forming a length of the stretch film wound around first means for preforming the package located on the feed table and mobile between several working positions where the tubular length of film is stretched open wide, the group of products fed into it, and the wrapped package fed back out onto the feed line once the stretch film has shrunk back to its original size.        
This first station may be followed, further downstream, by a structurally similar station, preceded by a station for turning the package through ninety degrees, to wrap the package with a second tubular length of film.
A machine of this type, although reliable and fulfilling its purpose, has inherent speed limitations which make it unable to fully meet the requirements of modern packaging houses, where wrapping speed is of the utmost importance.
The present invention therefore has for an aim to provide an apparatus for making packages of products wrapped with stretch plastic film that is at once extremely flexible and capable of achieving high production speeds without reducing wrapping quality and reliability.